According to a prior art, a bottom panel of a ceiling lamp is usually equipped to a ceiling, and then, a fastener is fixed to the bottom panel using screws. This kind of fixing has a complicated structure. Specifically, when equipping the ceiling lamp, an operator should use professional tools to screw multiple screws between bottom panel and the fastener, so that the fastener is fixed to the bottom panel. The mounting requires complicated work and costs time. Further, when repairing the ceiling lamp, the operator should use professional tools to remove the screws screwed between the bottom panel and the fastener in order to depart the fastener from the bottom panel. The dismounting of the fastener requires complicated work and costs time. As described above, conventional mounting of the fastener to the bottom panel and conventional dismounting of the fastener from the bottom panel requires complicated work, and needs higher manpower cost and time cost. Thus, this kind of fastener cannot satisfy increasing needs of the user for the lamps.